The person above you will post a word in another language (with an English translation, of course). You then write and translate the first word that comes to your mind into a new post. This can help with vocabulary, both in English and your foreign languages!
An example chain could be:
Post 1 wrote:[flag]fr[/flag] chien dog
Post 2 wrote:[flag]de[/flag] Katze cat
Post 3 wrote:[flag]tr[/flag] kürk fur
[flag]ko[/flag] 나무 tree